The present invention relates to a gas deionization device notably designed to be placed in the zone of the outlet orifice of an arc extinguishing chamber of a multipole low voltage circuit breaker with a molded case, and an arc extinguishing chamber equipped with this device.
Devices are known comprising fine-mesh metallic grates or shields, notably made of steel, housed in the outlet orifices of circuit breaker arc extinguishing chambers. The breaking gases are generated in the arc extinguishing chamber when circuit breaking takes place. The breaking gases are passed to the outside environment after passing through the grates acting as flame protection shields. It has however been observed that these gases were still highly ionized when outlet from the arc extinguishing chamber.
In order to improve deionization by cooling the breaking gases, other deionization devices have been previously proposed, notably a labyrinth formed by a plurality of shields with offset windows, a reflecting grate etc., but the large size of these devices does not enable them to be used in compact arc extinguishing chambers for molded case circuit breakers.
The European Patent EP 0,022,708 describes a deionization device comprising a porous shield formed from agglomerated balls made from a copper base. Gaps are arranged between the balls to enable the breaking gases to pass to the outside environment. This device of compact structure enables a relatively efficient cooling of the breaking gases ventilated from an arc extinguishing chamber with a high breaking capacity to be achieved.